Preheating boiler feed-water



y 1934- R. M. OSTERMANN PREHEATING BOILER FEED WATER I Filed Oct. 14, 1931 INVENTOR fiudolfMflflermamq BY ATTORNEY Patented May 8, 1934 UNITED STATES PATENT OFFICE Rudolf M. Ostermann, Kenilworth, 1H,, assignor to The Superheater Company, New York, N. Y.

Application October 14, 1931, Serial No. 568,751

1 Claim.

My invention relates to the art of supplying feed-water to fire tube boilers.

It has been attempted heretofore to avoid the known bad effects of supplying cold water to fire 3 tube boilers by spraying the feedwater into the steam space of the boiler to thereby raise its temperature before it can touch the tubes or shell of the boiler.

It has been found, however, that when a fine enough spray is formed to permit the feedwater to attain the desired temperature, a good deal of water is carried into the steam pipe, the so called dry pipe, and thence into the cylinders or superheater.

It is an object of my invention to provide a novel arrangement whereby the above mentioned difiiculty and its consequences may be minimized.

In accordance with my invention, a chamber is provided in the boiler by a partition running somewhat above and below the water line and placed relatively near the smokebox tube sheet. The chamber thus provided is connected both to the main steam space and to the main water space of the boiler. The feedwater is introduced into the chamber in such a way that steam is drawn into the chamber and contacted with the incoming water in the necessary quantity and manner to heat the water substantially to the 3 temperature of the steam in the boiler.

The novel features of my invention are pointed out with particularity in the appended claim. In order, however, that my invention, together with its objects and advantages, may be more fully understood, I will now describe, by way of example and in connection with the accompanying drawing, a particular feedwater arrangement for a locomotive which is an embodiment of my invention.

-0 In the drawing,

Fig. 1 is a longitudinal sectional elevation of a locomotive having a feedwater chamber adjacent the front flue sheet in accordance with my invention;

Fig. 2 is a section on line 22 of Fig. 1; and

Fig. 3 is a detail on an enlarged scale of the spray valve shown in Fig. 1.

The locomotive type boiler illustrated in the drawing has an-outer shell 10 within which is an ordinary fire box chamber 12 and smoke box chamber 14 connected by fire tubes, some of which are shown at 16, 16. These fire tubes 16 extend between the rear flue sheet 18 and a front fiue sheet 20. Within shell 10 and immediately adjacent the front flue sheet 20 is an open-bottomed feedwater chamber 22 formed by parts of the boiler and a partition or wall 24 which lies in a vertical plane somewhat to the rear of the plane of sheet 20. As shown, wall 24 contacts around its upper and outer edge with the inner face of shell 10, and extends downwardly well below the normal water level 26 in shell 10, but has no connection with other members along its lower edge, so that water in chamber 22 is in free communication with the main body of water in the boiler. An equalizing pipe or connection 30 is employed whereby the pressure of the steam in chamber 22 is maintained the same as that in steam space 28 at the rear of wall 24, connection 30 being shown as a pipe extending outside the shell 10 from a point close to the rear face of partition 24 to a point about midway of the chamber 22 where it is connected through the hood 38 so as to deliver into chamber 22 through an aperture 32.

In accordance with my invention, feedwater for the boiler 10 is delivered into chamber 22 in such a manner as to be heated substantially to the temperature of the steam in the boiler before contacting with the tubes 16. In the arrangement shown, the feedwater is introduced through a spray valve 34 so arranged in plate 35 in hood 38 that the water is sprayed downwardly through the aperture 32 into chamber 22. As clearly shown the feedwater passes downward through the full height of the steam space in the chamber 22 as well as through some distance in the hood 38 while in direct contact with steam at full boiler pressure so that it becomes heated substantially to the temperature of the saturated steam before striking the water in the boiler at level 26. The valve 34 is normally held seated by spring 36 which acts on a plate fixed to the stem of valve 34, the spring 36 and the valve stem being housed in a small chamber 39 in the top of hood 38 into which the feedwater is delivered by a pipe 40. When no water is delivered into the chamber 39 the valve 34 therefore remains closed, but is opened automatically by the water pressure when feedwater is to be delivered to the boiler 10. It will be seen that partition 24-. extends sufficiently below the water level 26 so that the feedwater delivered into chamber 22 is directed downwardly against the forward ends of the fire tubes 16 before it can pass along the boiler toward the fire box and the section where the heating gases in fines 16 are at higher temperature. In order to facilitate quick heating of the feedwater and separation of air therefrom, partition 24 may have openings 6, 6 therein.

In the operation of the arrangement above described, the water pasing thru valve 34 exerts an aspirating effect which draws through the connection 30 suflicient steam to heat the feedwater to the desired degree irrespective of the rate of supply of the feedwater. The chamber 22 being at the end of the boiler removed from the flunace not enough steam is generated immediately below such chamber to ensure that the feedwater shall always be heated to the desired degree.

In the arrangement shown, I have illustrated a known type of feedwater heater 42 for preheating the feedwater to some extent before it is delivered to chamber 22. As illustrated, the feedwater outlet of the heater 42 connects to the pipe 40, cold feedwatcr being delivered to heater 42 through pipe 44 in which is the feed pump 45. Steam for heating the water in device 42 may be taken from the exhaust nozzle by a pipe 48 and the condensate formed from such steam in the feedwater heater 42 delivered into pipe 44 through a pipe 50 at a point on the inlet side of the pump 46.

While I have shown and described in detail a particular arrangement in which the feedwater is heated by steam before mixing with the Water in chamber 22, I do not limit myself to any particular means for this purpose, but may use instead any known or preferred means for heating the feedwater to steam temperature before it strikes the water in chamber 22.

It will be seen that the arrangement described not only is effective in preventing fine particles of water from floating into the steam pipe of the boiler but that any scale forming substances in the feedwater contact first with sections of the tubes 16 near the outlet ends of the tubes, so that any scale formed will deposit principally on the parts of the tubes in contact with cooler furnace gases thereby localizing the scale formed in the zone in which its presence on the tubes has a minimum effect in cutting down the boiler capacity and in causing overheating of the metal of the tubes.

What I claim is:

The combination in a boiler having a fire box, a flue sheet near said fire box, a second flue sheet spaced therefrom, and horizontal fire tubes extending between said flue sheets of a wall Within said boiler forming a chamber therein beginning at the one of said sheets farther from said fire box and extending toward said fire box a minor portion only of the length of said tubes, said chamber lying immediately above the portions of said tubes adjacent said farther fiue sheet and having its bottom entirely open but arranged to substantially prevent the escape of spray from the chamber into the remainder of the boiler, a connection for leading steam from the steam space of the boiler into the upper portion of said chamber, and means for introducing feed water into the steam portion of said chamber, so ar ranged that the feed water is materially preheated before it strikes the boiler water.

RUDOLF M. OSTERNIANN. 

